A landmark study of Indigenous prisoners in Darwin and Alice Springs shows more than 90 per cent have hearing problems ranging from mild to severe.

The authors of the study say the finding is shocking and reflects the high rates of ear disease among Indigenous children.

It also raises questions about how much inmates with hearing problems understand the criminal justice system.

Dr Damian Howard, a Northern Territory psychologist specialising in patients with hearing loss and co-author of the study, says revelations of hearing loss also raise questions about whether prisoners have been fairly treated by the criminal justice process.

He says some cases may need to be reviewed.

"In terms of the safety of their convictions that really highlights importance of carrying out investigations that do answer those questions," he said.

Dr Howard says the prevalence of hearing loss is dramatic.

"About 6 to 7 per cent of non-Indigenous adults are likely to have a similar level of hearing loss," he said.

"So when you look at 6 per cent amongst non-Indigenous adults, 30 per cent amongst Indigenous adults in remote communities to over 90 per cent amongst Indigenous inmates, you can see that is a huge prevalence of hearing loss."

And he says the results point to a damning cycle of social dysfunction.

"It very much suggests that people having a hearing loss contributes to them becoming imprisoned, either through the hearing loss contributing to them having antisocial behaviour and/or that once they come to the attention of police and courts, their hearing loss in those settings, their communication difficulties leads to them being arrested, charged and found guilty and sentenced," Dr Howard said.

Last year a Senate inquiry found that Indigenous Australians suffer ear disease and hearing loss at possibly the highest rate of any people in the world.

The problems usually begin with middle ear infection, which can cause permanent hearing loss if untreated.

Factors like smoking, overcrowding, and poor nutrition make it more difficult for the infection to clear up.

Dr Howard says for many Indigenous people, ear infections begin in childhood and these prisoners are no different.

"There are clear indications that as young children, they had many ear health problems and there are also comments in terms of 76 per cent of the inmates tested describe having difficulties communicating with correction staff," he said.

While it might seem remarkable that hearing problems have not been picked up by authorities, Darwin Correctional Centre Acting Superintendent, Robert Miller, says it is not easy.

"Their first language is not necessarily English so you particularly wouldn't pick up that maybe there is a hearing loss, maybe there is just a communication barrier that is crossed using different techniques the prison officers use, so it would not have stood out as being an issue," he said.

Acting Superintendent Miller says the prison is now trialling new devices for inmates which he hopes in the future will also prevent reoffending.

"The prisoner can actually use his own ear phones that he would use normally for his walkman or radio. He can plug that into a hearing assisted device and it actually just amplifies the voice of the person that he is trying to listen," he said.

"They are possibly not getting the correct education because they can't hear correctly.

"We know education and employment are the basic things, in the agency's view, that will start preventing recidivism because you are getting people back in the community, becoming part of their community, a useful member of their community and being employed."

Acting Superintendent Miller says it will take a long time to determine whether recidivism rates do fall, but what he would like to see is that every prisoner will have a hearing device to take with them into the community when they are released.